Die and process for the manufacture of smokeless powder



1940- c. w. STEFFEN 2,210,011

DIE AND PRDCESS FOR THE MANUFACTURE OF SMOKELESS POWDER Filed Dec.,10, 1957 FIG. I FIG-2 CHARLES W. STEFFEN INVENTOR ATTORNEY Patented Aug. 6, 1940 UNITE DIE AND PROCESS FOR THE MANUFACTURE OF SMOKELESS POWDER Application December 10, 1937, Serial No. 179,200

7 Claims.

This invention relates to an improved process of manufacture of colloided smokeless powder.

Heretofore, in the manufacture of smokeless powder, nitrocellulose has been colloided by the use of a solvent to a dense colloid, and, if desired, with the addition of nitroglycerine or the like. This plastic colloid has then been pressed through dies to form strands of the desired diameter, if desired, having one or more central perforations therein, and the strands then cut to grains.

In the manufacture of smokeless powder as above, the dies through which the plastic colloid is pressed have been made heretofore of hardened steel. I have found that when dense colloided smokeless powder is made by using, instead of fresh fibrous nitrocellulose, a ground or otherwise disintegrated scrap smokeless powder suitably softened to a plastic colloid by the use of solvents, an extreme wear of hardened steel press dies occurs. For example, when pressing 285 lbs. of colloid through a steel die into 155 mm. howitzer powder strands, the die enlarged from .0675 to .0720 inches, thus rendering the die useless, and requiring frequent and costly replacement. Harder steel is notfavorable on account of brittleness and lack of strength, but much to my surprise I have found that by the use of Monel metal in dies, this wear is very much less than when using hardened steel dies, using the same quantity of colloid. This was not to be expected, because Monel metal is an extremely soft metal, and could not be expected to resist wear under these severe conditions.

When using Monel metal dies and pressing the same powder as above in the same quantities as above, the wear was only from .0675 to .0685, or in other words, a life 4 times as great with Monel metal dies as with hardened steel dies.

Having now indicated in a general way the nature and purpose of this invention there follows a more detailed description of the preferred embodiment thereof, with reference to the accompanying drawing in which: Figure l is an elevation view of a die and Figure 2 is a plan View of the die of Figure 1.

The die I of this invention is constructed of Monel metal and contains a single hole 2 centrally located within the body of the die. The die I is of heavy construction to withstand the pressure necessary to cause the smokeless powder colloid to extrude through the hole 2. The die I is designed to have a funnel shape entrance 3 to the die hole 2, as this type design greatly facilitates the extrusion operation. The groove 4 which extends around the die I is so placed to aid in maintaining the die in an adapter, not shown. The type press, in which the dieis to be used, will determine the type adapter necessary and since this procedure is well within the skill of the art the press and adapter are not depicted.

The die I of this invention as willbe obvious to those familiar with the art may be fitted with pin to produce perforated powder grains if so desired and this pin will be included as part of the adapter.

I do not limit my invention to any particular kind of dense colloided smokeless powder, but I may use my invention in the manufacture of smokeless powder prepared by the use of fibrous nitrocellulose, which while not as severe onthe die as smokeless powder prepared by the use of reworked smokeless powder, naturally causes a very considerable wear upon the dies. I may use my invention in the preparation of any desired size, shape, or form of strand of dense colloided powder, and such strands may be solid, as in the case of the usual cordite, or may have a single perforation as in the case of a small arms powder, or may be multi-perforated as in the case of cannon powders. I may use my invention-in the preparation of smokeless powder containing no nitroglycerine, i. e., the so-called pyro powders, or I may use my invention in the preparation of double base smokeless powder i. e., with powder containing varying proportions of nitroglycerine.

What I claim and desire to protect by Letters Patent is:

1. In a method of preparation of dense, colloided smokeless powder, the step consisting of pressing a nitrocellulose colloid thru a single hole forming die consisting of Monel metal.

2. In a method of preparation of dense, colloided smokeless powder, the step consisting of pressing a nitrocellulose colloid thru a single hole forming die consisting of Monel metal, said die being adapted to produce a tubular powder strand.

3. In a method of preparation'of dense, colloided smokeless powder, the step consisting of pressing a nitrocellulose colloid thru a single hole forming die consisting of Monel metal, said die being adapted to produce a multitubular powder strand.

4. In a .method of preparation of dense, colloided, double base smokeless powder, the step consisting of pressinga double base, nitrocellulose colloid thru a single hole forming die consisting of Monel metal.

5. A single hole die for smokeless powder presses, said die consisting of Monel metal and adapted to produce multiperforated strands of pressed material.

6. A single hole, die for smokeless powder 

